For the Bards, Jesters Cap and Gravitas
 

Is there a way to be able to always see which people have the immunity effect from these two abilities?

Would be great if there was some UI mod perhaps on the raid window similar to the priests heal buttons for every person, that would act similar to the maintained/detrimental spell window. An icon next to each persons name with a little time counter ticking down from 120 seconds after you apply the ability to that person.

That would be so awesome!

not possible